The presented review of publications is devoted to the study of the genetic and epigenetic foundations of the adaptation processes of living organisms, in particular, plants. The great interest in this topic is explained by its importance in understanding evolutionary changes and the mechanisms of conservation of populations and species. The article discusses the issues of genetic control of adaptively significant plant traits (flowering time and seed dormancy) and epigenetic mechanisms of regulation of the genes activity, which responsible for adaptation processes using the model species Arabidopsis thaliana. Various strategies of plant life cycles are described, based on the timing of seed germination and the time of the beginning of flowering, the adaptive value of which can vary depending on the climate. It is assumed that such heterogeneity of life strategies is a kind of insurance of populations against the risk of extinction. Analysis of literature data allowed us to use three canonical genes - FLC, FT, DOG1, identified by researchers as key ones in the control of adaptively significant plant traits and to consider the mechanisms of regulation of their activity under various environmental conditions. The review presents the molecular mechanisms that coordinate gene activity at the transcriptional level: chromatin modifications, histone methylation, participation of microRNA (miRNA) and long noncoding antisense RNA (lincRNA) in the suppression of gene expression, alternative splicing, alternative polyadenylation, activation of gene expression using the bZIP transcription factor and some others. It has been established that one of the important mechanisms of adaptation is adaptive pleiotropy, suggesting that seed dormancy and flowering may be coordinately regulated through overlapping molecular pathways.